Reductionism Redux: How Some Forms of Reduction Preserve Psychology’s Person-Level Subject Matter

Psychology’s historical alignment with the ontologies and epistemologies of natural science gave rise to the lamentations of theoretical psychologists who find therein a reductive treatment of what they regard as psychology’s legitimate subject matter—mental life, lived experience, and/or personhood in sociocultural discursive contexts. Concerns about inadequate treatment of this subject matter have led to charges of widespread positivist-inspired reductionism, applied by psychologists who reject natural-science methods to those psychologists who use them. A frequent position forwarded by these critics of mainstream psychology is that reductive practices eliminate psychological phenomena broadly construed. We challenge this view, demonstrating how some philosophers of science have claimed to avoid eliminating psychological phenomena and theories in their conceptions of reduction. We introduce the distinction between vertical (downward or upward interlevel) reduction and horizontal (intralevel) reduction to demonstrate how reduction in psychology is not always biologically downward in direction, as psychological phenomena are sometimes reduced to and explained at the sociocultural discursive level (upward reduction) and are often conceptualized and explained at the person level (horizontal reduction). We advocate a pragmatic, pluralistic turn in scientific psychology, in asking theoretical psychologists to consider more nuanced understandings of reduction as found in other human-science disciplines (e.g., sociology). We aim to advance appreciation of the productive, responsible uses of reduction that get lost in dismissing reduction in psychology summarily.